Zoe becomes a Death Walker in New Cap City
A Death Walker (Deadwalker) is an avatar trapped in V-World.
Daniel Graystone created an avatar of Tamara Adama by combining the collection of her memories and experiences with a copy of his daughter's sentient avatar program.
Since Tamara was created, and not a real human being, she cannot exit V-World because she has no body to which she can return. To the other players, who do not know about her origin, she is dead in the real world and thus unable to awaken. ("Pilot") ("There Is Another Sky") ("Unvanquished")
After Zoe (as the U-87) crashes the van in her attempt to escape to Gemenon, she ends up in New Cap City, unable to return to her robot body. ("End of Line") ("Unvanquished")